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Stopping two cars

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Imax
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Stopping two cars

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I was on my way to work on a divided four lane highway. I was in the right hand lane following the flow of traffic. There was a slower car ahead of me and I wanted to change lanes and maintain my speed. When I looked in my left side mirror, I notice a red car going pretty fast in the passing lane, so I slowed down and waited. Once the speeder had passed my car the passing lane was clear. I changed lanes, accelerated a bit, and started to overtake the slower car. I was just about to go back in the right hand lane when the speeder (still in the passing lane) put on its brakes, so I put on my brakes. The speeder put on its brakes again, so I put on my brakes again. At that point I figured there must be an accident or something, but I couldnt see anything in front of me, except a speeder trying to slow down. For a split second, I was thinking of going back in the right hand lane, but after putting on the brakes twice, I had lost track to the slower car in the right hand lane. So, I stayed in the passing lane behind the speeder and we both went slower and slower. We were crawling along in the passing lane when I noticed a police cruiser parked on the left. I figured the officer nabbed the speeder, and I was going to go along my marry way. The speeder stopped on the left side of the road and then the officer signalled me to stop as well, so I did. He claimed he clocked me doing 127 kph in a 100 zone. Im pretty sure he had the speeder clocked at 130 kph, and Im sure I wasnt going that fast. Could the officer have made a mistake, given the speeder was in front of me from the point I changed lanes?

I was on my way to work on a divided four lane highway. I was in the right hand lane following the flow of traffic. There was a slower car ahead of me and I wanted to change lanes and maintain my speed. When I looked in my left side mirror, I notice a red car going pretty fast in the passing lane, so I slowed down and waited. Once the speeder had passed my car the passing lane was clear. I changed lanes, accelerated a bit, and started to overtake the slower car. I was just about to go back in the right hand lane when the speeder (still in the passing lane) put on its brakes, so I put on my brakes. The speeder put on its brakes again, so I put on my brakes again. At that point I figured there must be an accident or something, but I couldnt see anything in front of me, except a speeder trying to slow down. For a split second, I was thinking of going back in the right hand lane, but after putting on the brakes twice, I had lost track to the slower car in the right hand lane. So, I stayed in the passing lane behind the speeder and we both went slower and slower. We were crawling along in the passing lane when I noticed a police cruiser parked on the left. I figured the officer nabbed the speeder, and I was going to go along my marry way. The speeder stopped on the left side of the road and then the officer signalled me to stop as well, so I did. He claimed he clocked me doing 127 kph in a 100 zone. Im pretty sure he had the speeder clocked at 130 kph, and Im sure I wasnt going that fast. Could the officer have made a mistake, given the speeder was in front of me from the point I changed lanes?

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ticketcombat
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Re: Stopping two cars

If the cop was using lidar (laser) then he could get the speed of both vehicles individually. It also means he has to take his eyes off one vehicle to target the other vehicle. If it's radar then he couldn't get the speed of both vehicles. If the first vehicle is a Yukon and you're in a smart car, it would be pretty hard to see you. If it's the other way around, it would be easy to observe both vehicles. Request disclosure. It will tell you what he saw, what he did and what he used.

If the cop was using lidar (laser) then he could get the speed of both vehicles individually. It also means he has to take his eyes off one vehicle to target the other vehicle. If it's radar then he couldn't get the speed of both vehicles.

If the first vehicle is a Yukon and you're in a smart car, it would be pretty hard to see you. If it's the other way around, it would be easy to observe both vehicles.

Request disclosure. It will tell you what he saw, what he did and what he used.

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Imax
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Re: Stopping two cars

Hi ticketcombat: Is that your site? Lots of useful info. Thanks

Hi ticketcombat:

Is that your site? Lots of useful info.

Thanks

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Reflections
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Re: Stopping two cars

Disclosure it is. I really doubt that the officer could reliably get your speed with the other car in front of you. If the officer was using lidar then he could have sampled the speed of the passing car twice, once before he hit the brakes and once while he was slowing, and attributed it to you. Disclosure is a must. The disclosure should list the distance of the measurement...this will come into play later..... as well as the make and model of the unit. Ask for the officers notes as far back as the beginning of his/her shift, that is when they do their alignment test. If your speeder boy is lucky, and in court the same day as you, you can call each other as witnesses.....

Disclosure it is. I really doubt that the officer could reliably get your speed with the other car in front of you. If the officer was using lidar then he could have sampled the speed of the passing car twice, once before he hit the brakes and once while he was slowing, and attributed it to you. Disclosure is a must. The disclosure should list the distance of the measurement...this will come into play later..... as well as the make and model of the unit. Ask for the officers notes as far back as the beginning of his/her shift, that is when they do their alignment test. If your speeder boy is lucky, and in court the same day as you, you can call each other as witnesses.....

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Re: Stopping two cars

Yes it is my site and thanks for the positive feedback. I would even go further than reflection's suggestions. In the disclosure request I would ask for the contact information of the "witness" which is the driver of the other vehicle. Why leave it up to chance that you'll bump into him in court? Most people pay the fine. Better still, they probably won't give you the info which means you can argue improper disclosure and stay the charge.

Yes it is my site and thanks for the positive feedback.

I would even go further than reflection's suggestions. In the disclosure request I would ask for the contact information of the "witness" which is the driver of the other vehicle. Why leave it up to chance that you'll bump into him in court? Most people pay the fine. Better still, they probably won't give you the info which means you can argue improper disclosure and stay the charge.

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hwybear
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Re: Stopping two cars

Absolutely, very easy to do obtain all speeds on all 3 vehicles.

Reflections wrote:

Disclosure it is. I really doubt that the officer could reliably get your speed with the other car in front of you.

Absolutely, very easy to do obtain all speeds on all 3 vehicles.

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Re: Stopping two cars

FYI, we do not give complete notes for our whole shift. Only applicable notes for the incident in question

Reflections wrote:

Ask for the officers notes as far back as the beginning of his/her shift, that is when they do their alignment test.

FYI, we do not give complete notes for our whole shift. Only applicable notes for the incident in question

Above is merely a suggestion/thought and in no way constitutes legal advice or views of my employer. www.OHTA.ca
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Re: Stopping two cars

Im certain many officers have no problems placing crosshairs of a laser on any car in traffic, but the light beam coming out of a laser is not a small dot. Most lasers have a beam that diverges at a rate of about 30cm/100m. That means your dot is really a 30cm circle at 100m. Go to 300m and the circle grows to 90cm, or about 3 feet. Any car going inside that 3 foot circle can interfere with readings on the intended target.

Im certain many officers have no problems placing crosshairs of a laser on any car in traffic, but the light beam coming out of a laser is not a small dot. Most lasers have a beam that diverges at a rate of about 30cm/100m. That means your dot is really a 30cm circle at 100m. Go to 300m and the circle grows to 90cm, or about 3 feet. Any car going inside that 3 foot circle can interfere with readings on the intended target.

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Re: Stopping two cars

You ticket was required to be issued in both French and English by the cop because the demerit points are a provincial matter. The province has guaranteed you services and procedures will be provided in both languages even if you don't speak both languages. It's not an option. My advice is that you do not respond to the ticket at all and file an appeal within 15 days of receiving the conviction notice. You will then argue that the ticket was defective on its face for not being in both languages and the Justice was required by law to quash the proceeding. If you bring this information forward now, or request a trail to explain it, the court can fix it and you will be found guilty and a fine and points will be imposed, along with possibly higher insurance rates. The only way to prevent the court from fixing a ticket with errors is to not respond to it at all. The Provincial Offences Act articulates that laying a charge is a procedure under Part I and III. The French Language Services Act guarantees you that all services and procedures will be provided in both French and English. Provincial Offences Act Certificate of offence and offence notice http://www.e-laws.gov.on.ca/html/statut ... _e.htm#BK4 3. (1) In addition to the procedure set out in Part III for commencing a proceeding by laying an information, a proceeding in respect of an offence may be commenced by filing a certificate of offence alleging the offence in the office of the court. Commencement of proceeding by information 21. (1) In addition to the procedure set out in Parts I and II for commencing a proceeding by the filing of a certificate, a proceeding in respect of an offence may be commenced by laying an information. French Language Services Act Definitions 1. In this Act, http://www.e-laws.gov.on.ca/html/statut ... 0f32_e.htm "service" means any service or procedure that is provided to the public by a government agency or institution of the Legislature and includes all communications for the purpose.

You ticket was required to be issued in both French and English by the cop because the demerit points are a provincial matter. The province has guaranteed you services and procedures will be provided in both languages even if you don't speak both languages. It's not an option.

My advice is that you do not respond to the ticket at all and file an appeal within 15 days of receiving the conviction notice. You will then argue that the ticket was defective on its face for not being in both languages and the Justice was required by law to quash the proceeding.

If you bring this information forward now, or request a trail to explain it, the court can fix it and you will be found guilty and a fine and points will be imposed, along with possibly higher insurance rates.

The only way to prevent the court from fixing a ticket with errors is to not respond to it at all.

The Provincial Offences Act articulates that laying a charge is a procedure under Part I and III.

The French Language Services Act guarantees you that all services and procedures will be provided in both French and English.

Provincial Offences Act

Certificate of offence and offence notice

http://www.e-laws.gov.on.ca/html/statut ... _e.htm#BK4

3. (1) In addition to the procedure set out in Part III for commencing a proceeding by laying an information, a proceeding in respect of an offence may be commenced by filing a certificate of offence alleging the offence in the office of the court.

Commencement of proceeding by information

21. (1) In addition to the procedure set out in Parts I and II for commencing a proceeding by the filing of a certificate, a proceeding in respect of an offence may be commenced by laying an information.

French Language Services Act

Definitions

1. In this Act,

http://www.e-laws.gov.on.ca/html/statut ... 0f32_e.htm

"service" means any service or procedure that is provided to the public by a government agency or institution of the Legislature and includes all communications for the purpose.

Last edited by lawmen on Tue Nov 18, 2008 7:17 pm, edited 1 time in total.
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Re: Stopping two cars

The only thing that would happen is NO reading at all if two targets were to happen to get in the beam.

Imax wrote:

Any car going inside that 3 foot circle can interfere with readings on the intended target.

The only thing that would happen is NO reading at all if two targets were to happen to get in the beam.

Above is merely a suggestion/thought and in no way constitutes legal advice or views of my employer. www.OHTA.ca
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Re: Stopping two cars

Your alignment check is part of the incident Depends on vehicle gapping and your distance to target. 400 meters to target = 1.2 meter (4 feet) diameter beam, plus any angle to the road also increases the diameter. If you can accurately site 3 vehicles front licence plates at that distance, I'll personally deliver you a Boston Cream and Cafe Mocha. :D

FYI, we do not give complete notes for our whole shift. Only applicable notes for the incident in question

Your alignment check is part of the incident

Absolutely, very easy to do obtain all speeds on all 3 vehicles.

Depends on vehicle gapping and your distance to target. 400 meters to target = 1.2 meter (4 feet) diameter beam, plus any angle to the road also increases the diameter. If you can accurately site 3 vehicles front licence plates at that distance, I'll personally deliver you a Boston Cream and Cafe Mocha. :D

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Re: Stopping two cars

Better start driving then :wink: ps...I don't want a day old either...I am a professional donut taster and know the difference!!

Reflections wrote:

. If you can accurately site 3 vehicles front licence plates at that distance, I'll personally deliver you a Boston Cream and Cafe Mocha. :D

Better start driving then :wink:

ps...I don't want a day old either...I am a professional donut taster and know the difference!!

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Re: Stopping two cars

I'm sure this belongs in traffic jokes but here goes: Officer: Mr Reflections, where are we going in such a hurry? Me: I lost this stupid bet with a cop and I have to get him his prize. Officer: And why do you need to drive so fast?? Me: He's a professional and demands results. Officer: Results?? Me: This donut and Tims are fresh........Where did they go??? Officer: Wherrrrr'd whaaat go (gulp)? Me: Officer, you have Boston Cream on your chin. Officer: No I don't. Me: Officer, I need to get another donut. Where's the closest Tim's?? Officer: Next exit, turn right. Tell Sally I say hi. You had better get two donuts. Me: Why? Officer: There's another officer just past that exit and he knows your coming.

I'm sure this belongs in traffic jokes but here goes:

Officer: Mr Reflections, where are we going in such a hurry?

Me: I lost this stupid bet with a cop and I have to get him his prize.

Officer: And why do you need to drive so fast??

Me: He's a professional and demands results.

Officer: Results??

Me: This donut and Tims are fresh........Where did they go???

Officer: Wherrrrr'd whaaat go (gulp)?

Me: Officer, you have Boston Cream on your chin.

Officer: No I don't.

Me: Officer, I need to get another donut. Where's the closest Tim's??

Officer: Next exit, turn right. Tell Sally I say hi. You had better get two donuts.

Me: Why?

Officer: There's another officer just past that exit and he knows your coming.

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Re: Stopping two cars

:lol: :lol: :lol:

:lol: :lol: :lol:

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Re: Stopping two cars

Hi Reflections: Thats funny! But I wouldnt drive to my nearest Tims if I were you, unless Hwybear has figured out a way to upgrade his laser with gamma rays or x-rays.

Hi Reflections:

Thats funny! But I wouldnt drive to my nearest Tims if I were you, unless Hwybear has figured out a way to upgrade his laser with gamma rays or x-rays.

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Re: Stopping two cars

I'm willing to bet the officer just assumed you were traveling at the same speed as the lead car. I wouldn't put a lot of thought in to a defense until you read the Disclosure. The type of equipment the officer used will make all the difference in how you handle your questioning. I suspect the Crown will be anxious to offer a plea to a lesser charge, but I would hold off on accepting that until you carefully go over the officers notes. Bear might be correct in that his equipment is 100% foolproof, but how it is used is definitely up for argument.

I'm willing to bet the officer just assumed you were traveling at the same speed as the lead car.

I wouldn't put a lot of thought in to a defense until you read the Disclosure. The type of equipment the officer used will make all the difference in how you handle your questioning.

I suspect the Crown will be anxious to offer a plea to a lesser charge, but I would hold off on accepting that until you carefully go over the officers notes. Bear might be correct in that his equipment is 100% foolproof, but how it is used is definitely up for argument.

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Re: Stopping two cars

My offer of you coming to visit when I'm working and showing you the tools is still there!! Once you see it and use the equipment, you will then understand the equipment better AND know why it is accurate! AS compared to the videos show on various sites and that they are not used properly.

Bookm wrote:

Bear might be correct in that his equipment is 100% foolproof, but how it is used is definitely up for argument.

My offer of you coming to visit when I'm working and showing you the tools is still there!!

Once you see it and use the equipment, you will then understand the equipment better AND know why it is accurate! AS compared to the videos show on various sites and that they are not used properly.

Above is merely a suggestion/thought and in no way constitutes legal advice or views of my employer. www.OHTA.ca
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Re: Stopping two cars

My offer of you coming to visit when I'm working and showing you the tools is still there!! Once you see it and use the equipment, you will then understand the equipment better AND know why it is accurate! AS compared to the videos show on various sites and that they are not used properly. Those video's still show the gun is not fool proof. You could be using it properly and still have unseen influences. Until you can see the beam while in flight questions remain. The amount of "noise" filtering going on is unbelievable. Don't worry there Imax, I can see the limitations of the guns.

hwybear wrote:

Bookm wrote:

Bear might be correct in that his equipment is 100% foolproof, but how it is used is definitely up for argument.

My offer of you coming to visit when I'm working and showing you the tools is still there!!

Once you see it and use the equipment, you will then understand the equipment better AND know why it is accurate! AS compared to the videos show on various sites and that they are not used properly.

Those video's still show the gun is not fool proof. You could be using it properly and still have unseen influences. Until you can see the beam while in flight questions remain. The amount of "noise" filtering going on is unbelievable.

Don't worry there Imax, I can see the limitations of the guns.

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Re: Stopping two cars

Last month I received data that showed a survey bar in the middle of the street. When I asked my party-chief, "What the heck?", he came to the realization that the laser reflected off the taillight of a passing car instead of his prism. This may not happen with police systems, but a JP might entertain the possibility :P Will let you know when I get my next tick' ;) Now,... when I come I want you to show me how you can ID speeds of two cars in a line using RADAR, hehehe

Last month I received data that showed a survey bar in the middle of the street. When I asked my party-chief, "What the heck?", he came to the realization that the laser reflected off the taillight of a passing car instead of his prism.

This may not happen with police systems, but a JP might entertain the possibility :P

Will let you know when I get my next tick' ;)

Now,... when I come I want you to show me how you can ID speeds of two cars in a line using RADAR, hehehe

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Re: Stopping two cars

Absoletely not! If you have a video that I can see to the contrary PM me the link. And not the england guy who stands 50 seats away from the edge of the road.

Reflections wrote:

You could be using it properly and still have unseen influences.

Absoletely not!

If you have a video that I can see to the contrary PM me the link. And not the england guy who stands 50 seats away from the edge of the road.

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Re: Stopping two cars

Im a nerd by nature, :oops: , and last night I did a few computations. The officer was standing at approx. 10m off the road. Minimum stooping distance for a car going 130kph is just over 80m, screech, screech, panic brake. Controlled stopping distance for a car going 130Kph is about 200m to 400m. I was about 100 to 200 feet behind the lead car, min 30m to max 100m. The officer could have measured lead car speed at 300m, 400m, or 500m. If I remember my trig ok, best case scenario is that when the officer moved his laser from the lead car to my car (following the speeder), the laser would need to be moved by less than ½ of a degree. Most probable scenario is 0.1 to 0.2 degrees. He must be s sharp shooter. 8)

Im a nerd by nature, :oops:, and last night I did a few computations. The officer was standing at approx. 10m off the road. Minimum stooping distance for a car going 130kph is just over 80m, screech, screech, panic brake. Controlled stopping distance for a car going 130Kph is about 200m to 400m. I was about 100 to 200 feet behind the lead car, min 30m to max 100m. The officer could have measured lead car speed at 300m, 400m, or 500m. If I remember my trig ok, best case scenario is that when the officer moved his laser from the lead car to my car (following the speeder), the laser would need to be moved by less than ½ of a degree. Most probable scenario is 0.1 to 0.2 degrees. He must be s sharp shooter. 8)

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Re: Stopping two cars

It helps that the lidar has a scope that is magnified 8 times.

Imax wrote:

He must be s sharp shooter. 8)

It helps that the lidar has a scope that is magnified 8 times.

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Re: Stopping two cars

Bear, first I want to state that I've never held or used a lidar gun so all of my knowledge is only from what I've read. With that in mind, here are some questions for you: The scope is offset from where the laser pulse is emitted. How is it aligned for different distances? I'm thinking of every sniper movie I've ever seen, even Day of the Jackal (the original) where he's shooting the pumpkin from a distance. He has to keep modifying the scope settings to get the aim right. How do you align the scope when your road targets can be at 50m or 250m? The fixed distance test - is there an alignment mark on the unit so that it measures precisely where the pulse is emitted from. If the tester has his foot on the line, he could be leaning forward or back (not perfectly vertical). How do you compensate for this? Is the unit placed on a fixed stand?

Bear, first I want to state that I've never held or used a lidar gun so all of my knowledge is only from what I've read. With that in mind, here are some questions for you:

  • The scope is offset from where the laser pulse is emitted. How is it aligned for different distances? I'm thinking of every sniper movie I've ever seen, even Day of the Jackal (the original) where he's shooting the pumpkin from a distance. He has to keep modifying the scope settings to get the aim right. How do you align the scope when your road targets can be at 50m or 250m?

  • The fixed distance test - is there an alignment mark on the unit so that it measures precisely where the pulse is emitted from. If the tester has his foot on the line, he could be leaning forward or back (not perfectly vertical). How do you compensate for this? Is the unit placed on a fixed stand?

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Re: Stopping two cars

Absoletely not! If you have a video that I can see to the contrary PM me the link. And not the england guy who stands 50 seats away from the edge of the road. I will hunt...... The nature of lidar is such that it will bounce off of everything and anything. All the manufacturer's claim 1/3 third of a second readings, yet none will say exactly how they are filtering the noise. There is too much left out to conclusively say they are perfect.

hwybear wrote:

Reflections wrote:

You could be using it properly and still have unseen influences.

Absoletely not!

If you have a video that I can see to the contrary PM me the link. And not the england guy who stands 50 seats away from the edge of the road.

I will hunt...... The nature of lidar is such that it will bounce off of everything and anything. All the manufacturer's claim 1/3 third of a second readings, yet none will say exactly how they are filtering the noise. There is too much left out to conclusively say they are perfect.

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Re: Stopping two cars

I'm no great fan of having laser beams pointed at me while I'm driving, but I don't think parallax is an issue. The laser beam is not significantly affected by gravity and has no wind resistance, so the "error" between the sightline of the scope and the centre of the beam would be a constant 2.5cm (or whatever is the distance between the two at the unit) and easily compensated out in the course of signal processing. It is only if Officer Friendly were trying to shoot me in the head with his long-range rifle as I drove on my unconcerned way down the 401 that he would have to consider bullet rise and drop over time and distance, wind effects, possible legal complications, and the effects of parallax error with changing distance to target. Whether or not they're accurate in measuring speeds, the use of lasers around highways bugs me. Unfriendly folks are using them to disrupt big-time soccer games by shining them at players to momentarily blind them, and the same delightful hobby is showing up around airports, with pilots on short finals being the target. How is the highway situation different?

ticketcombat wrote:

The scope is offset from where the laser pulse is emitted. How is it aligned for different distances?

I'm no great fan of having laser beams pointed at me while I'm driving, but I don't think parallax is an issue. The laser beam is not significantly affected by gravity and has no wind resistance, so the "error" between the sightline of the scope and the centre of the beam would be a constant 2.5cm (or whatever is the distance between the two at the unit) and easily compensated out in the course of signal processing. It is only if Officer Friendly were trying to shoot me in the head with his long-range rifle as I drove on my unconcerned way down the 401 that he would have to consider bullet rise and drop over time and distance, wind effects, possible legal complications, and the effects of parallax error with changing distance to target.

Whether or not they're accurate in measuring speeds, the use of lasers around highways bugs me. Unfriendly folks are using them to disrupt big-time soccer games by shining them at players to momentarily blind them, and the same delightful hobby is showing up around airports, with pilots on short finals being the target. How is the highway situation different?

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Re: Stopping two cars

Hmmm... I've been thinking about getting a laser parking system to assist with those tricky parking situations. Gee, I hope the Laser Pro Park system won't negatively affect the police lasers ;)

Hmmm... I've been thinking about getting a laser parking system to assist with those tricky parking situations. Gee, I hope the Laser Pro Park system won't negatively affect the police lasers ;)

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Re: Stopping two cars

Is that what they're calling them now :o

Bookm wrote:

Hmmm... I've been thinking about getting a laser parking system to assist with those tricky parking situations. Gee, I hope the Laser Pro Park system won't negatively affect the police lasers ;)

Is that what they're calling them now :o

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Re: Stopping two cars

I'm no great fan of having laser beams pointed at me while I'm driving, but I don't think parallax is an issue. The laser beam is not significantly affected by gravity and has no wind resistance, so the "error" between the sightline of the scope and the centre of the beam would be a constant 2.5cm (or whatever is the distance between the two at the unit) and easily compensated out in the course of signal processing. It is only if Officer Friendly were trying to shoot me in the head with his long-range rifle as I drove on my unconcerned way down the 401 that he would have to consider bullet rise and drop over time and distance, wind effects, possible legal complications, and the effects of parallax error with changing distance to target. Whether or not they're accurate in measuring speeds, the use of lasers around highways bugs me. Unfriendly folks are using them to disrupt big-time soccer games by shining them at players to momentarily blind them, and the same delightful hobby is showing up around airports, with pilots on short finals being the target. How is the highway situation different? Lidar used by officers is invisible to the naked eye. You can however use nightvision to see them. I wonder why officers are not using nightvision to align the scopes??? Paralax become an issue when you aim out at say 500m or so when the beam will be higher then the target, i.e lisence plate. If an officer wants to use the gun past that distance then all the power to him and easier for me to beat in court. One thing though. I know that light travels at a constant speed in a vacuum. The atmosphere is not a vacuum. Dirt, smog.....all those airbourne particles can effect light. How would this be compensated for....? I know you're coming back to this 'bear so..... The further away a target is from the gun the more the "light" is going to slow down, simple physics. Is there a setting you have for "smoggy" days??? I know there are foul weather modes on different models. You cannot compensate for the unknown.

Proper1 wrote:

ticketcombat wrote:

The scope is offset from where the laser pulse is emitted. How is it aligned for different distances?

I'm no great fan of having laser beams pointed at me while I'm driving, but I don't think parallax is an issue. The laser beam is not significantly affected by gravity and has no wind resistance, so the "error" between the sightline of the scope and the centre of the beam would be a constant 2.5cm (or whatever is the distance between the two at the unit) and easily compensated out in the course of signal processing. It is only if Officer Friendly were trying to shoot me in the head with his long-range rifle as I drove on my unconcerned way down the 401 that he would have to consider bullet rise and drop over time and distance, wind effects, possible legal complications, and the effects of parallax error with changing distance to target.

Whether or not they're accurate in measuring speeds, the use of lasers around highways bugs me. Unfriendly folks are using them to disrupt big-time soccer games by shining them at players to momentarily blind them, and the same delightful hobby is showing up around airports, with pilots on short finals being the target. How is the highway situation different?

Lidar used by officers is invisible to the naked eye. You can however use nightvision to see them. I wonder why officers are not using nightvision to align the scopes???

Paralax become an issue when you aim out at say 500m or so when the beam will be higher then the target, i.e lisence plate. If an officer wants to use the gun past that distance then all the power to him and easier for me to beat in court.

One thing though. I know that light travels at a constant speed in a vacuum. The atmosphere is not a vacuum. Dirt, smog.....all those airbourne particles can effect light. How would this be compensated for....? I know you're coming back to this 'bear so..... The further away a target is from the gun the more the "light" is going to slow down, simple physics. Is there a setting you have for "smoggy" days??? I know there are foul weather modes on different models. You cannot compensate for the unknown.

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Re: Stopping two cars

Hopefully they've tested the lidar units to ensure that they won't blind a driver who's being clocked. Officer: "Why didn't you stop when I waved you over?" Driver: "I was driving along and suddenly I couldn't see!!" :shock: The hand-held laser pointers, the type that've been directed at aircraft, can do a lot of damage. Last winter we were landing in Detroit and some moron was shining them at inbound aircraft. We asked for a different runway, whose approach course was over a mile from where this idiot was. So did everyone else after the first plane reported being illuminated by a laser. Knowing the potential consequences of having a laser beam directed at your eyes, you'd really hope that the types in the lidar units are almost certain not to do the same sort of thing.

Hopefully they've tested the lidar units to ensure that they won't blind a driver who's being clocked.

Officer: "Why didn't you stop when I waved you over?"

Driver: "I was driving along and suddenly I couldn't see!!"

:shock:

The hand-held laser pointers, the type that've been directed at aircraft, can do a lot of damage. Last winter we were landing in Detroit and some moron was shining them at inbound aircraft. We asked for a different runway, whose approach course was over a mile from where this idiot was. So did everyone else after the first plane reported being illuminated by a laser. Knowing the potential consequences of having a laser beam directed at your eyes, you'd really hope that the types in the lidar units are almost certain not to do the same sort of thing.

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Re: Stopping two cars

Our fixed distance is done at the corner of the wall. The lidar is held flush with the wall or on a tripod flush with the wall. The known target distance was measured out by tape to where posts were placed in the ground.

ticketcombat wrote:

[*]The fixed distance test - is there an alignment mark on the unit so that it measures precisely where the pulse is emitted from. If the tester has his foot on the line, he could be leaning forward or back (not perfectly vertical). How do you compensate for this? Is the unit placed on a fixed stand?[/list]

Our fixed distance is done at the corner of the wall. The lidar is held flush with the wall or on a tripod flush with the wall. The known target distance was measured out by tape to where posts were placed in the ground.

Above is merely a suggestion/thought and in no way constitutes legal advice or views of my employer. www.OHTA.ca

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